NO idea why this popped into my head today (probably cuz there's a lot of room there!).
I remember that as a kid when I used to cut lawns for people, one of my neighbors bought, and I used, a lawnmower that didn't have any wheels, but when started would 'glide' above the ground on air it produced. Obviously it appears that this was a "technology" that never caught on, because I never saw another one, but does anyone else remember ever seeing one of these? Just curious.